Road headers, also known as roadheading machines or heading machines, are heavy-duty excavation equipment used in tunneling and underground construction projects.
Definition:
Road headers, also known as roadheading machines or heading machines, are heavy-duty excavation equipment used in tunneling and underground construction projects. They are designed to excavate rock or hard soil in a continuous process by cutting, breaking, and loading the material onto a conveyor for removal from the tunnel.
Uses/benefits:
1. Tunnel excavation: Road headers are primarily used for tunnel excavation in various underground structures, including transportation tunnels, mining tunnels, and utility tunnels. They are capable of cutting through hard rock formations efficiently, allowing for the construction of tunnels of different shapes and sizes.
2. High productivity: Road headers offer high excavation rates, enabling rapid progress in tunneling projects. Their continuous cutting and loading process reduces downtime and increases overall productivity compared to conventional drilling and blasting methods.
3. Safety and precision: Road headers provide a safer working environment by eliminating the need for manual drilling and blasting. They offer precise control over the excavation process, minimizing the risk of accidental damage to the surrounding rock mass or underground structures.
4. Versatility: Road headers can adapt to various geological conditions and rock types, including hard rock, coal seams, and compacted soils. They can be equipped with different cutting attachments and tools to accommodate specific ground conditions.
5. Reduced environmental impact: Compared to drilling and blasting methods, road headers generate less noise, vibration, and airborne dust during excavation, resulting in reduced environmental impact and improved working conditions for personnel.
Specifications:
1. Cutting power: Road headers are equipped with powerful cutting heads that use disc cutters or drum cutters to break and remove the rock or soil. The cutting power is a crucial specification that determines the machine's ability to handle different rock formations.
2. Machine size and weight: Road headers come in various sizes and weights, depending on the project requirements and the tunnel dimensions. Smaller road headers are suitable for narrow tunnels or areas with space constraints, while larger models are used for larger-scale tunneling projects.
3. Excavation capacity: The excavation capacity of road headers refers to the amount of material they can cut and load per unit of time. It depends on factors such as the cutting speed, cutting mechanism, and conveyor capacity.
4. Power source: Road headers can be powered by electricity or diesel engines. The choice of power source depends on factors such as project requirements, available infrastructure, and environmental considerations.
5. Steering and maneuverability: Road headers are designed with features that allow them to navigate through the tunnel and make directional changes when necessary. These features include articulated booms, hydraulic steering systems, and flexible cutting heads.
Types:
1. Drum-type Road headers: These road headers have a rotating drum equipped with cutting picks or bits. The drum cuts into the rock or soil, and the excavated material is loaded onto a conveyor for removal.
2. Boom-type Road headers: These road headers have an articulated boom with a cutting head at the end. The cutting head can be equipped with disc cutters or other cutting tools to break and remove the material.
3. Full-face road headers: Full-face Road headers are capable of cutting the entire tunnel profile in a single pass. They are used for tunnels with larger cross-sections and require high productivity.
4. Partial-face Road headers: Partial-face Road headers are used for tunnels with smaller cross-sections or when selective excavation is required. They are equipped with cutting heads that can be adjusted to match the tunnel profile.
The selection of road headers depends on factors such as the geological conditions, tunnel dimensions, project requirements, and available infrastructure.